2.0.56.android4 release

benchmark/pom.xml

@@ -6,7 +6,7 @@
     <parent>
         <groupId>com.alibaba.fastjson2</groupId>
         <artifactId>fastjson2-parent</artifactId>
-        <version>2.0.55.android5</version>
+        <version>2.0.56.android5</version>
         <relativePath>../pom.xml</relativePath>
     </parent>
 

codegen-test/pom.xml

@@ -6,7 +6,7 @@
     <parent>
         <groupId>com.alibaba.fastjson2</groupId>
         <artifactId>fastjson2-parent</artifactId>
-        <version>2.0.55.android5</version>
+        <version>2.0.56.android5</version>
         <relativePath>../pom.xml</relativePath>
     </parent>
 

core/pom.xml

@@ -6,7 +6,7 @@
     <parent>
         <groupId>com.alibaba.fastjson2</groupId>
         <artifactId>fastjson2-parent</artifactId>
-        <version>2.0.55.android5</version>
+        <version>2.0.56.android5</version>
         <relativePath>../pom.xml</relativePath>
     </parent>
 

core/src/main/java/com/alibaba/fastjson2/JSON.java

@@ -32,7 +32,7 @@ public interface JSON {
     /**
      * fastjson2 version name
      */
-    String VERSION = "2.0.55";
+    String VERSION = "2.0.56";
 
     /**
      * Parses the json string as a {@link JSONArray} or {@link JSONObject}.

core/src/main/java/com/alibaba/fastjson2/JSONReader.java

@@ -3794,6 +3794,7 @@ public abstract class JSONReader
             }
         }
     }
+    protected static final long MASK_DISABLE_REFERENCE_DETECT = 1L << 33;
 
     public enum Feature {
         FieldBased(1),
@@ -3917,7 +3918,12 @@ public abstract class JSONReader
         /**
          * @since 2.0.53
          */
-        UseDoubleForDecimals(1L << 32L);
+        UseDoubleForDecimals(1L << 32L),
+
+        /**
+         * @since 2.0.56
+         */
+        DisableReferenceDetect(MASK_DISABLE_REFERENCE_DETECT);
 
         public final long mask;
 

core/src/main/java/com/alibaba/fastjson2/JSONReaderUTF16.java

@@ -154,8 +154,10 @@ final class JSONReaderUTF16
         return bytes;
     }
 
-    @Override
     public final boolean isReference() {
+        if ((context.features & MASK_DISABLE_REFERENCE_DETECT) != 0) {
+            return false;
+        }
         // should be codeSize <= FreqInlineSize 325, current is 276
         final char[] chars = this.chars;
         char ch = this.ch;
@@ -188,6 +190,11 @@ final class JSONReaderUTF16
             return false;
         }
 
+        return isReference0(chars, offset, end, quote);
+    }
+
+    private boolean isReference0(char[] chars, int offset, int end, char quote) {
+        char ch;
         offset += 6;
         ch = chars[offset];
         while (ch <= ' ' && ((1L << ch) & SPACE) != 0) {
@@ -211,7 +218,9 @@ final class JSONReaderUTF16
             ch = chars[offset];
         }
 
-        if (ch != quote || (offset + 1 < end && chars[offset + 1] == '#')) {
+        if (ch != quote
+                || (offset + 1 < end && (ch = chars[offset + 1]) != '$' && ch != '.' && ch != '@')
+        ) {
             return false;
         }
 

core/src/main/java/com/alibaba/fastjson2/JSONReaderUTF8.java

@@ -16,6 +16,8 @@ import static java.nio.charset.StandardCharsets.UTF_8;
 
 class JSONReaderUTF8
         extends JSONReader {
+    static final int REF = BIG_ENDIAN ? 0x24726566 : 0x66657224;
+
     protected final byte[] bytes;
     protected final int length;
     protected final int start;
@@ -4683,8 +4685,11 @@ class JSONReaderUTF8
     }
 
     @Override
-    public boolean isReference() {
+    public final boolean isReference() {
         // should be codeSize <= FreqInlineSize 325, current : 284
+        if ((context.features & MASK_DISABLE_REFERENCE_DETECT) != 0) {
+            return false;
+        }
         final byte[] bytes = this.bytes;
         int ch = this.ch;
         if (ch != '{') {
@@ -4705,17 +4710,18 @@ class JSONReaderUTF8
             ch = bytes[offset];
         }
 
-        int quote = ch;
         if (offset + 6 >= end
-                || bytes[offset + 1] != '$'
+                || bytes[offset + 5] != ch
-                || bytes[offset + 2] != 'r'
+                || UNSAFE.getInt(bytes, ARRAY_BYTE_BASE_OFFSET + offset + 1) != REF
-                || bytes[offset + 3] != 'e'
-                || bytes[offset + 4] != 'f'
-                || bytes[offset + 5] != quote
         ) {
             return false;
         }
 
+        return isReference0(bytes, offset, end, ch);
+    }
+
+    private boolean isReference0(byte[] bytes, int offset, int end, int quote) {
+        int ch;
         offset += 6;
         ch = bytes[offset];
         while (ch >= 0 && ch <= ' ' && ((1L << ch) & SPACE) != 0) {
@@ -4739,7 +4745,9 @@ class JSONReaderUTF8
             ch = bytes[offset];
         }
 
-        if (ch != quote || (offset + 1 < end && bytes[offset + 1] == '#')) {
+        if (ch != quote
+                || (offset + 1 < end && (ch = bytes[offset + 1]) != '$' && ch != '.' && ch != '@')
+        ) {
             return false;
         }
 

core/src/main/java/com/alibaba/fastjson2/annotation/JSONField.java

@@ -121,4 +121,9 @@ public @interface JSONField {
      * @since 2.0.52
      */
     Class<?> arrayToMapDuplicateHandler() default Void.class;
+
+    /**
+     * @since 2.0.56
+     */
+    Class<?> contentAs() default Void.class;
 }

core/src/main/java/com/alibaba/fastjson2/codec/FieldInfo.java

@@ -20,6 +20,7 @@ public class FieldInfo {
     public static final long DISABLE_REFERENCE_DETECT = 1L << 58;
     public static final long BACKR_EFERENCE = 1L << 61;
     public static final long RECORD = 1L << 62;
+    public static final long CONTENT_AS = 1L << 63;
 
     public String fieldName;
     public String format;
@@ -44,6 +45,11 @@ public class FieldInfo {
     public String arrayToMapKey;
     public Class<?> arrayToMapDuplicateHandler;
 
+    /**
+     * @since 2.0.56
+     */
+    public Class<?> contentAs;
+
     public ObjectReader getInitReader() {
         Class<?> calzz = readUsing;
         if (calzz != null && ObjectReader.class.isAssignableFrom(calzz)) {
@@ -94,5 +100,6 @@ public class FieldInfo {
 
         arrayToMapKey = null;
         arrayToMapDuplicateHandler = null;
+        contentAs = null;
     }
 }

core/src/main/java/com/alibaba/fastjson2/writer/FieldWriterList.java

@@ -21,6 +21,7 @@ abstract class FieldWriterList<T>
     ObjectWriter listWriter;
     ObjectWriter itemObjectWriter;
     final boolean writeAsString;
+    final Class<?> contentAs;
 
     FieldWriterList(
             String name,
@@ -32,9 +33,11 @@ abstract class FieldWriterList<T>
             Type fieldType,
             Class fieldClass,
             Field field,
-            Method method
+            Method method,
+            Class<?> contentAs
     ) {
         super(name, ordinal, features, format, label, fieldType, fieldClass, field, method);
+        this.contentAs = contentAs;
 
         writeAsString = (features & WriteNonStringValueAsString.mask) != 0;
 
@@ -74,6 +77,13 @@ abstract class FieldWriterList<T>
 
     @Override
     public ObjectWriter getItemWriter(JSONWriter jsonWriter, Type itemType) {
+        if (contentAs != null) {
+            ObjectWriter itemObjectWriter = this.itemObjectWriter;
+            if (itemObjectWriter != null) {
+                return itemObjectWriter;
+            }
+            return this.itemObjectWriter = jsonWriter.getObjectWriter(this.contentAs, contentAs);
+        }
         if (itemType == null || itemType == this.itemType) {
             if (itemObjectWriter != null) {
                 return itemObjectWriter;

core/src/main/java/com/alibaba/fastjson2/writer/FieldWriterListField.java

@@ -19,9 +19,10 @@ final class FieldWriterListField<T>
             String label,
             Type fieldType,
             Class fieldClass,
-            Field field
+            Field field,
+            Class<?> contentAs
     ) {
-        super(fieldName, itemType, ordinal, features, format, label, fieldType, fieldClass, field, null);
+        super(fieldName, itemType, ordinal, features, format, label, fieldType, fieldClass, field, null, contentAs);
     }
 
     @Override

core/src/main/java/com/alibaba/fastjson2/writer/FieldWriterListFunc.java

@@ -23,9 +23,10 @@ final class FieldWriterListFunc<T>
             Method method,
             Function<T, List> function,
             Type fieldType,
-            Class fieldClass
+            Class fieldClass,
+            Class<?> contentAs
     ) {
-        super(fieldName, itemType, ordinal, features, format, label, fieldType, fieldClass, null, method);
+        super(fieldName, itemType, ordinal, features, format, label, fieldType, fieldClass, null, method, contentAs);
         this.function = function;
     }
 

core/src/main/java/com/alibaba/fastjson2/writer/FieldWriterListMethod.java

@@ -23,9 +23,10 @@ final class FieldWriterListMethod<T>
             Field field,
             Method method,
             Type fieldType,
-            Class fieldClass
+            Class fieldClass,
+            Class<?> contentAs
     ) {
-        super(fieldName, itemType, ordinal, features, format, label, fieldType, fieldClass, field, method);
+        super(fieldName, itemType, ordinal, features, format, label, fieldType, fieldClass, field, method, contentAs);
     }
 
     @Override

core/src/main/java/com/alibaba/fastjson2/writer/FieldWriterMap.java

@@ -0,0 +1,86 @@
+package com.alibaba.fastjson2.writer;
+
+import com.alibaba.fastjson2.JSONWriter;
+import com.alibaba.fastjson2.codec.FieldInfo;
+import com.alibaba.fastjson2.util.ParameterizedTypeImpl;
+import com.alibaba.fastjson2.util.TypeUtils;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+import java.lang.reflect.ParameterizedType;
+import java.lang.reflect.Type;
+
+abstract class FieldWriterMap
+        extends FieldWriterObject {
+    protected final Class<?> contentAs;
+    protected Type contentAsFieldType;
+    volatile ObjectWriter mapWriter;
+    private final Type keyType;
+    private final Type valueType;
+    final boolean valueTypeRefDetect;
+    volatile ObjectWriter valueWriter;
+
+    protected FieldWriterMap(
+            String name,
+            int ordinal,
+            long features,
+            String format,
+            String label,
+            Type fieldType,
+            Class fieldClass,
+            Field field,
+            Method method,
+            Class<?> contentAs
+    ) {
+        super(name, ordinal, features, format, label, fieldType, fieldClass, field, method);
+        Type keyType = null, valueType = null;
+        Type contentAsFieldType = null;
+        if (fieldType instanceof ParameterizedType) {
+            ParameterizedType pt = (ParameterizedType) fieldType;
+            Type[] actualTypeArguments = pt.getActualTypeArguments();
+            if (actualTypeArguments.length == 2) {
+                keyType = actualTypeArguments[0];
+                valueType = actualTypeArguments[1];
+            }
+        }
+        if (keyType == null) {
+            keyType = Object.class;
+        }
+        if (valueType == null) {
+            valueType = Object.class;
+        }
+        if (contentAs != null) {
+            contentAsFieldType = new ParameterizedTypeImpl(fieldClass, String.class, contentAs);
+        }
+        this.contentAs = contentAs;
+        this.contentAsFieldType = contentAsFieldType;
+        this.keyType = keyType;
+        this.valueType = valueType;
+        this.valueTypeRefDetect = !ObjectWriterProvider.isNotReferenceDetect(TypeUtils.getClass(valueType));
+    }
+
+    @Override
+    public ObjectWriter getObjectWriter(JSONWriter jsonWriter, Class valueClass) {
+        Class<?> contentAs = this.contentAs;
+        if (contentAs == null || !fieldClass.isAssignableFrom(valueClass)) {
+            return super.getObjectWriter(jsonWriter, valueClass);
+        }
+
+        ObjectWriter valueWriter = this.valueWriter;
+        if (valueWriter != null) {
+            return valueWriter;
+        }
+
+        Type fieldType = this.fieldType;
+        Type valueType = this.valueType;
+        long features = this.features;
+        if (contentAs != null) {
+            valueType = contentAs;
+            fieldType = contentAsFieldType;
+            features |= FieldInfo.CONTENT_AS;
+        }
+        valueWriter = new ObjectWriterImplMap(keyType, valueType, valueClass, fieldType, features);
+        this.mapWriter = valueWriter;
+        return valueWriter;
+    }
+}

core/src/main/java/com/alibaba/fastjson2/writer/FieldWriterMapField.java

@@ -0,0 +1,23 @@
+package com.alibaba.fastjson2.writer;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+import java.lang.reflect.Type;
+
+final class FieldWriterMapField
+        extends FieldWriterMap {
+    FieldWriterMapField(
+            String name,
+            int ordinal,
+            long features,
+            String format,
+            String label,
+            Type fieldType,
+            Class fieldClass,
+            Field field,
+            Method method,
+            Class<?> contentAs
+    ) {
+        super(name, ordinal, features, format, label, fieldType, fieldClass, field, method, contentAs);
+    }
+}

core/src/main/java/com/alibaba/fastjson2/writer/FieldWriterMapFunction.java

@@ -0,0 +1,33 @@
+package com.alibaba.fastjson2.writer;
+
+import com.alibaba.fastjson2.function.Function;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+import java.lang.reflect.Type;
+
+final class FieldWriterMapFunction
+        extends FieldWriterMap {
+    final Function function;
+    FieldWriterMapFunction(
+            String name,
+            int ordinal,
+            long features,
+            String format,
+            String label,
+            Type fieldType,
+            Class fieldClass,
+            Field field,
+            Method method,
+            Function function,
+            Class<?> contentAs
+    ) {
+        super(name, ordinal, features, format, label, fieldType, fieldClass, field, method, contentAs);
+        this.function = function;
+    }
+
+    @Override
+    public Object getFieldValue(Object object) {
+        return function.apply(object);
+    }
+}

core/src/main/java/com/alibaba/fastjson2/writer/FieldWriterMapMethod.java

@@ -0,0 +1,35 @@
+package com.alibaba.fastjson2.writer;
+
+import com.alibaba.fastjson2.JSONException;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.lang.reflect.Type;
+
+final class FieldWriterMapMethod
+        extends FieldWriterMap {
+    FieldWriterMapMethod(
+            String name,
+            int ordinal,
+            long features,
+            String format,
+            String label,
+            Type fieldType,
+            Class fieldClass,
+            Field field,
+            Method method,
+            Class<?> contentAs
+    ) {
+        super(name, ordinal, features, format, label, fieldType, fieldClass, field, method, contentAs);
+    }
+
+    @Override
+    public Object getFieldValue(Object object) {
+        try {
+            return method.invoke(object);
+        } catch (IllegalArgumentException | IllegalAccessException | InvocationTargetException e) {
+            throw new JSONException("invoke getter method error, " + fieldName, e);
+        }
+    }
+}

core/src/main/java/com/alibaba/fastjson2/writer/ObjectWriterCreator.java

@@ -223,7 +223,7 @@ public class ObjectWriterCreator {
             format = beanInfo.format;
         }
 
-        return createFieldWriter(provider, fieldName, fieldInfo.ordinal, fieldInfo.features, format, fieldInfo.label, field, writeUsingWriter);
+        return createFieldWriter(provider, fieldName, fieldInfo.ordinal, fieldInfo.features, format, fieldInfo.label, field, writeUsingWriter, fieldInfo.contentAs);
     }
 
     public ObjectWriter createObjectWriter(
@@ -362,7 +362,8 @@ public class ObjectWriterCreator {
                             fieldInfo.format,
                             fieldInfo.label,
                             method,
-                            writeUsingWriter
+                            writeUsingWriter,
+                            fieldInfo.contentAs
                     );
 
                     FieldWriter origin = fieldWriterMap.get(fieldWriter.fieldName);
@@ -574,6 +575,20 @@ public class ObjectWriterCreator {
             String label,
             Field field,
             ObjectWriter initObjectWriter
+    ) {
+        return createFieldWriter(provider, fieldName, ordinal, features, format, label, field, initObjectWriter, null);
+    }
+
+    public <T> FieldWriter<T> createFieldWriter(
+            ObjectWriterProvider provider,
+            String fieldName,
+            int ordinal,
+            long features,
+            String format,
+            String label,
+            Field field,
+            ObjectWriter initObjectWriter,
+            Class<?> contentAs
     ) {
         Class<?> declaringClass = field.getDeclaringClass();
         Method method = null;
@@ -701,7 +716,11 @@ public class ObjectWriterCreator {
             if (fieldType instanceof ParameterizedType) {
                 itemType = ((ParameterizedType) fieldType).getActualTypeArguments()[0];
             }
-            return new FieldWriterListField(fieldName, itemType, ordinal, features, format, label, fieldType, fieldClass, field);
+            return new FieldWriterListField(fieldName, itemType, ordinal, features, format, label, fieldType, fieldClass, field, contentAs);
+        }
+
+        if (Map.class.isAssignableFrom(fieldClass)) {
+            return new FieldWriterMapField(fieldName, ordinal, features, format, label, field.getGenericType(), fieldClass, field, null, contentAs);
         }
 
         if (fieldClass.isArray() && !fieldClass.getComponentType().isPrimitive()) {
@@ -739,6 +758,21 @@ public class ObjectWriterCreator {
             String label,
             Method method,
             ObjectWriter initObjectWriter
+    ) {
+        return createFieldWriter(provider, objectType, fieldName, ordinal, features, format, label, method, initObjectWriter, null);
+    }
+
+    public <T> FieldWriter<T> createFieldWriter(
+            ObjectWriterProvider provider,
+            Class<T> objectType,
+            String fieldName,
+            int ordinal,
+            long features,
+            String format,
+            String label,
+            Method method,
+            ObjectWriter initObjectWriter,
+            Class<?> contentAs
     ) {
         Class<?> fieldClass = method.getReturnType();
         Type fieldType = method.getGenericReturnType();
@@ -848,7 +882,11 @@ public class ObjectWriterCreator {
             } else {
                 itemType = Object.class;
             }
-            return new FieldWriterListMethod(fieldName, itemType, ordinal, features, format, label, field, method, fieldType, fieldClass);
+            return new FieldWriterListMethod(fieldName, itemType, ordinal, features, format, label, field, method, fieldType, fieldClass, contentAs);
+        }
+
+        if (Map.class.isAssignableFrom(fieldClass)) {
+            return new FieldWriterMapMethod(fieldName, ordinal, features, format, label, fieldType, fieldClass, field, method, contentAs);
         }
 
         if (fieldClass == Float[].class) {
@@ -933,6 +971,23 @@ public class ObjectWriterCreator {
             Class<V> fieldClass,
             Method method,
             Function<T, V> function
+    ) {
+        return createFieldWriter(provider, objectClass, fieldName, ordinal, features, format, label, fieldType, fieldClass, method, function, null);
+    }
+
+    public <T, V> FieldWriter<T> createFieldWriter(
+            ObjectWriterProvider provider,
+            Class<T> objectClass,
+            String fieldName,
+            int ordinal,
+            long features,
+            String format,
+            String label,
+            Type fieldType,
+            Class<V> fieldClass,
+            Method method,
+            Function<T, V> function,
+            Class<?> contentAs
     ) {
         if (fieldClass == Byte.class) {
             return new FieldWriterInt8Func(fieldName, ordinal, features, format, label, method, function);
@@ -1008,9 +1063,13 @@ public class ObjectWriterCreator {
                     if (itemType == String.class) {
                         return new FieldWriterListStrFunc(fieldName, ordinal, features, format, label, method, function, fieldType, fieldClass);
                     }
-                    return new FieldWriterListFunc(fieldName, ordinal, features, format, label, itemType, method, function, fieldType, fieldClass);
+                    return new FieldWriterListFunc(fieldName, ordinal, features, format, label, itemType, method, function, fieldType, fieldClass, contentAs);
                 }
             }
+
+            if (rawType instanceof Class && Map.class.isAssignableFrom((Class<?>) rawType)) {
+                return new FieldWriterMapFunction(fieldName, ordinal, features, format, label, fieldType, fieldClass, null, method, function, contentAs);
+            }
         }
 
         if (Modifier.isFinal(fieldClass.getModifiers())) {

core/src/main/java/com/alibaba/fastjson2/writer/ObjectWriterImplMap.java

@@ -1,6 +1,7 @@
 package com.alibaba.fastjson2.writer;
 
 import com.alibaba.fastjson2.*;
+import com.alibaba.fastjson2.codec.FieldInfo;
 import com.alibaba.fastjson2.filter.*;
 import com.alibaba.fastjson2.util.*;
 
@@ -43,6 +44,8 @@ public final class ObjectWriterImplMap
     final char[] typeInfoUTF16;
     final byte[] typeInfoUTF8;
 
+    final boolean contentAs;
+
     public ObjectWriterImplMap(Class objectClass, long features) {
         this(null, null, objectClass, objectClass, features);
     }
@@ -59,6 +62,7 @@ public final class ObjectWriterImplMap
         } else {
             this.valueTypeRefDetect = !ObjectWriterProvider.isNotReferenceDetect(TypeUtils.getClass(valueType));
         }
+        contentAs = (features & FieldInfo.CONTENT_AS) != 0;
 
         String typeName = TypeUtils.getTypeName(objectClass);
         String typeInfoStr = "\"@type\":\"" + objectClass.getName() + "\"";
@@ -148,7 +152,12 @@ public final class ObjectWriterImplMap
 
             jsonWriter.writeString(key);
 
-            Class<?> valueType = value.getClass();
+            Class valueType;
+            if (contentAs) {
+                valueType = (Class) this.valueType;
+            } else {
+                valueType = value.getClass();
+            }
             if (valueType == String.class) {
                 jsonWriter.writeString((String) value);
             } else {
@@ -279,7 +288,12 @@ public final class ObjectWriterImplMap
                 }
             }
 
-            Class<?> valueClass = value.getClass();
+            Class valueClass;
+            if (contentAs) {
+                valueClass = (Class) this.valueType;
+            } else {
+                valueClass = value.getClass();
+            }
             if (valueClass == String.class) {
                 jsonWriter.writeString((String) value);
                 continue;
@@ -480,7 +494,12 @@ public final class ObjectWriterImplMap
             }
             jsonWriter.writeColon();
 
-            Class<?> valueClass = value.getClass();
+            Class valueClass;
+            if (contentAs) {
+                valueClass = (Class) this.valueType;
+            } else {
+                valueClass = value.getClass();
+            }
             if (valueClass == String.class) {
                 jsonWriter.writeString((String) value);
                 continue;
@@ -654,7 +673,12 @@ public final class ObjectWriterImplMap
                 if (value == null) {
                     jsonWriter.writeNull();
                 } else {
-                    Class<?> valueType = value.getClass();
+                    Class valueType;
+                    if (contentAs) {
+                        valueType = (Class) this.valueType;
+                    } else {
+                        valueType = value.getClass();
+                    }
                     ObjectWriter valueWriter = jsonWriter.getObjectWriter(valueType);
                     valueWriter.write(jsonWriter, value, fieldName, fieldType, this.features);
                 }

core/src/main/java/com/alibaba/fastjson2/writer/ObjectWriterProvider.java

@@ -634,6 +634,11 @@ public class ObjectWriterProvider {
         ) {
             fieldInfo.writeUsing = ObjectWriterImplToString.class;
         }
+
+        Class<?> contentAs = jsonField.contentAs();
+        if (contentAs != Void.class) {
+            fieldInfo.contentAs = contentAs;
+        }
     }
 
     private void processJSONField1x(FieldInfo fieldInfo, Annotation annotation) {

core/src/test/java/com/alibaba/fastjson2/features/ContentAsTest.java

@@ -0,0 +1,111 @@
+package com.alibaba.fastjson2.features;
+
+import com.alibaba.fastjson2.JSON;
+import com.alibaba.fastjson2.annotation.JSONField;
+import org.junit.jupiter.api.Test;
+
+import java.util.ArrayList;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class ContentAsTest {
+    class Vehicle {
+        private String type;
+
+        public Vehicle(String type) { this.type = type; }
+        public String getType() { return type; }
+    }
+
+    class Car
+            extends Vehicle {
+        private int seats;
+
+        public Car(String type, int seats) {
+            super(type);
+            this.seats = seats;
+        }
+        public int getSeats() { return seats; }
+    }
+
+    class Garage {
+        @JSONField(contentAs = Vehicle.class)
+        private List<Vehicle> vehicles = new ArrayList<>();
+
+        public void addVehicle(Vehicle v) { vehicles.add(v); }
+        public List<Vehicle> getVehicles() { return vehicles; }
+    }
+
+    @Test
+    public void test() throws Exception {
+        Garage garage = new Garage();
+        garage.addVehicle(new Car("Sedan", 5));
+        garage.addVehicle(new Car("SUV", 7));
+
+        assertEquals(
+                "{\"vehicles\":[{\"type\":\"Sedan\"},{\"type\":\"SUV\"}]}",
+                JSON.toJSONString(garage));
+    }
+
+    class GarageField {
+        @JSONField(contentAs = Vehicle.class)
+        public List<Vehicle> vehicles = new ArrayList<>();
+
+        public void addVehicle(Vehicle v) { vehicles.add(v); }
+    }
+
+    @Test
+    public void testField() throws Exception {
+        GarageField garage = new GarageField();
+        garage.addVehicle(new Car("Sedan", 5));
+        garage.addVehicle(new Car("SUV", 7));
+
+        assertEquals(
+                "{\"vehicles\":[{\"type\":\"Sedan\"},{\"type\":\"SUV\"}]}",
+                JSON.toJSONString(garage));
+    }
+
+    class GarageMap {
+        @JSONField(contentAs = Vehicle.class)
+        private Map<String, Vehicle> vehicles = new LinkedHashMap<>();
+
+        public void addVehicle(Vehicle v) {
+            vehicles.put(v.getType(), v);
+        }
+
+        public Map<String, Vehicle> getVehicles() {
+            return vehicles;
+        }
+    }
+
+    @Test
+    public void testMap() throws Exception {
+        GarageMap garage = new GarageMap();
+        garage.addVehicle(new Car("Sedan", 5));
+        garage.addVehicle(new Car("SUV", 7));
+
+        String json = JSON.toJSONString(garage);
+        assertEquals("{\"vehicles\":{\"Sedan\":{\"type\":\"Sedan\"},\"SUV\":{\"type\":\"SUV\"}}}", json);
+    }
+
+    class GarageMapField {
+        @JSONField(contentAs = Vehicle.class)
+        public Map<String, Vehicle> vehicles = new LinkedHashMap<>();
+
+        public void addVehicle(Vehicle v) {
+            vehicles.put(v.getType(), v);
+        }
+    }
+
+    @Test
+    public void testMapField() throws Exception {
+        GarageMapField garage = new GarageMapField();
+        garage.addVehicle(new Car("Sedan", 5));
+        garage.addVehicle(new Car("SUV", 7));
+
+        String json = JSON.toJSONString(garage);
+        assertEquals("{\"vehicles\":{\"Sedan\":{\"type\":\"Sedan\"},\"SUV\":{\"type\":\"SUV\"}}}", json);
+    }
+}

core/src/test/java/com/alibaba/fastjson2/issues_3300/Issue3347.java

@@ -0,0 +1,34 @@
+package com.alibaba.fastjson2.issues_3300;
+
+import com.alibaba.fastjson2.JSON;
+import com.alibaba.fastjson2.JSONObject;
+import com.alibaba.fastjson2.JSONReader;
+import org.junit.jupiter.api.Test;
+
+import java.nio.charset.StandardCharsets;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class Issue3347 {
+    @Test
+    public void test() {
+        String json2 = "{\"*/*\":{\"schema\":{\"$ref\":\"Error-ModelName{namespace='javax.servlet.http', name='HttpServletResponse'}\"}}}";
+        String expected = "Error-ModelName{namespace='javax.servlet.http', name='HttpServletResponse'}";
+        {
+            JSONObject jsonObject4 = JSON.parseObject(json2);
+            assertEquals(expected, jsonObject4.getJSONObject("*/*").getJSONObject("schema").getString("$ref"));
+        }
+        {
+            JSONObject jsonObject4 = JSON.parseObject(json2.getBytes(StandardCharsets.UTF_8));
+            assertEquals(expected, jsonObject4.getJSONObject("*/*").getJSONObject("schema").getString("$ref"));
+        }
+        {
+            JSONObject jsonObject4 = JSON.parseObject(json2.toCharArray());
+            assertEquals(expected, jsonObject4.getJSONObject("*/*").getJSONObject("schema").getString("$ref"));
+        }
+        {
+            JSONObject jsonObject4 = JSON.parseObject(json2, JSONReader.Feature.DisableReferenceDetect);
+            assertEquals(expected, jsonObject4.getJSONObject("*/*").getJSONObject("schema").getString("$ref"));
+        }
+    }
+}

pom.xml

@@ -6,7 +6,7 @@
 
     <groupId>com.alibaba.fastjson2</groupId>
     <artifactId>fastjson2-parent</artifactId>
-    <version>2.0.55.android5</version>
+    <version>2.0.56.android5</version>
     <name>${project.artifactId}</name>
     <description>Fastjson is a JSON processor (JSON parser + JSON generator) written in Java</description>
     <packaging>pom</packaging>